1. Field of the Invention
The present invention relates to a poultry brooder and, more specifically, to a poultry brooder in which a radiant element is suspended over a heat source such as a thermostatically controlled direct spark ignition gas burner. 2. Description of the Prior Art
Various attempts have heretofore been made to provide an efficient poultry brooder to be suspended in a poultry house for controlling brooding temperature. Maintaining proper brooding temperature is critical to effective poultry brooding since temperature variations cause chicks to expend energy to maintain body temperature rather than to increase body weight. Expending energy to increase body weight desirably results in larger, more saleable birds and enables chicks to resist disease. Thus, poultry house temperature variation can result in smaller, less desirable birds and can cause weaker chicks to contract diseases which, in turn, may spread to other chicks. Naturally, the poultry farmer desires to maximize productivity by producing as much meat as possible for the feed consumed. The desirable result is to keep the bird warm so that the food energy contained in the feed is used to produce weight gain rather than body heat.
A competing goal, however, is to obtain the desired warming of the chicks with minimum fuel consumption. Poultry farmers typically raise thousands of chicks using many poultry brooders. Consequently, the farmer desires the most fuel-efficient burner available to minimize energy costs.
Structures for maintaining temperature on a poultry house floor traditionally concentrate on radiating heat downward onto the chicks, either by being supported above the floor on a pedestal or suspended from the poultry house ceiling. Prior art structures have, for the most part, concentrated on distributing heat from a small heat source, typically a gas burner, over as great a floor surface area as possible.
One such structure is disclosed in U.S. Pat. No. 3,027,888 issued to Du Fault for POULTRY BROODERS. Du Fault discloses a spiral gas burner positioned within a cylindrical perforated screen beneath a flat deflecting plate. In operation, the Du Fault spiral gas burner increases the burner surface area to heat the perforated screen and flat deflecting plate, which spread heat over the poultry house floor. A similar structure is shown in U.S. Pat. No. 3,503,379 issued to Kuhn for RADIANT HEATING DEVICE, which discloses a ring-shaped burner to heat vertical screens, all beneath a deflecting plate.
In U.S. Pat. No. 2,985,137 issued to Horne for a CHICKEN BROODER, a perforated screen radiant is configured in an inverted frusto-conical shape to increase the surface area of the poultry house floor heated by this radiant. As with other perforated screen radiants, heated gas must penetrate the screen in order to heat that screen and cause it to radiate. Horne discloses a gas burner positioned above the perforated screen but below a baffle to accomplish full penetration of the screen by the hot gases. The baffle forces heated gases from the burner outward through the screen. Horne also discloses insulating the rear surface of the baffle to prevent heat from dissipating rather than being forced through the screen.
No prior art structures involving perforated screen radiants disclose any method for evenly controlling the heating of the radiant. Rather, in these structures the heated gas randomly passes or is forced through the perforated screen.
Structures which obtain more even heating of the radiant element involve inverted frusto-conical ceramic elements suspended above a gas burner which contact heated gases flowing outwardly across the radiant. One such structure is disclosed in U.S. Pat. No. 3,429,306 issued to Thompson for a GAS HEATING UNIT FOR BROODER. The ceramic element there disclosed is provided with projections on the lower surface thereof. In the Thompson brooder, however, the heated gas flows across the ceramic element by a direct path through the protrusions to the edge thereof.
Another brooder involving a ceramic radiant element is disclosed in U.S. Pat. No. 3,505,976 issued to Miller for a GAS FIRED CHICK BROODER DEVICE. There, a ceramic radiant element positioned above a gas burner and having randomly positioned projections on the bottom surface thereof is disclosed. The pitch of the bottom surface of the ceramic element varies from relatively steep near the center to relatively flat or even oppositely pitched at the outer edges in order to allow hot gases to travel across the ceramic element quickly at the center and more slowly at the edges thereof. However, as in the Thompson U.S. Pat. No. 3,429,306 structure, the heated gases flow to the edge of the ceramic element by a direct path between the projections. Such direct flow does not achieve even heating of the ceramic element.
None of the prior art structures which disclose a ceramic element heated by contact with hot gases to radiate energy downwardly discloses a structure which maximizes efficient heat transfer from the hot gases to the ceramic radiant element while also preventing inefficient heat loss to the surrounding environment.
All of the prior art gas fired poultry brooders include pilot burners for igniting the main gas burner. The pilot burners remain lit during all non-heating periods when the main burner is extinguished so that the main burner can be re-ignited on demand. It has been found that the fuel consumption of pilot burners alone can be considerable for poultry farmers who utilize many brooders. In addition, prior art pilot burner structures have often been found to become clogged by dust and particulate matter commonly found in poultry houses. Since the main burner cannot be ignited if the pilot burner is extinguished by clogging, the ultimate objective of heating the chicks can be defeated by pilot burner clogging. If proper safety features are not installed in the gas supply or if the safety features fail, extinguishing the pilot burner can also result in dangerous leakage of gas into the poultry house. Obviously, latent gas presents a hazard to both the farmer and the birds.
Another method of heating poultry houses is the "Whole House" method of heating. In that method, external air is heated and driven into the poultry house. Examples of the whole house method of heating poultry houses are discussed in the following U.S. patents issued to Frank J. Siccardi:
______________________________________ U.S. Pat. No. Issue Date Title ______________________________________ 4,278,423 July 14, 1981 Heating and Ventilating System for Poultry Houses 4,369,030 Jan. 18, 1983 System for Controlled Heating and Ventilating of Poultry Houses 4,524,722 June 25, 1985 Livestock Enclosure- Environmental Control Method ______________________________________
Typically, the whole house method of heating relies, at least in part, upon poultry brooders of the type to which the present invention relates. Therefore, poultry brooders compliment the whole house method and are not displaced thereby.
3. Objects of the Inventions
Accordingly, one object of the present invention is to provide a ceramic radiant element which is adapted to control the flow of hot gases thereover.
A further object of the present invention is to provide, in a ceramic radiant element adapted to control the flow of hot gases thereover, maximum energy transfer from the hot gases to the radiant element.
Yet a further object of the present invention is to minimize inefficient dissipation of energy by the radiant element to the atmosphere.
Another object of the present invention is to provide, in a thermostatically controlled poultry brooder, a safe and reliable ignition system.
A further object of the present invention is to provide a thermostatically controlled poultry brooder which does not rely upon a pilot burner ignition system to ignite the main burner during heating periods.
These and other highly desirable and unusual results are accomplished by the present invention in an economical structure which may be operated with little or no personal attention by the poultry farmer to attain remarkable fuel savings.
Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists in the novel parts, constructions, arrangements, combinations, steps, and improvements herein shown and described.